ZiLOG ZDS-1 Series User Manual page 17

Software Expansion
In addition t o the RIO Operating System Zilog provides a broad range of higher level languages to simplify
and accelerate microprocessor software development activity.
BASIC
Zilog's newest Extended BASIC Interpreter sets a new
standard in precision and speed performance for the most
popular microcomputer language. Two versions of the sys-
tem-a version of business BASIC with a 13-digit BDC data
type-and a scientific version w i t h the conventional 32-bit
floating binary data type-guarantee the optimal mix of
speed and precision for any application from professional
quality business data processing to extensive scientific cal-
culations. In both of these versions, a 16-bit integer data
type provides compact storage and rapid computation for
status and control variables. Finally, the string data type per-
mits manipulation of variable length text in a uniquely pow-
erful subscripted notation. Both interpreters have extensive
access to disk files through Zilog's ZDOSII disk operating
system.
Internally, the Zilog BASIC Interpreter has advanced the
state of the art in microcomputer language both in its math-
ematical packages and in its method of variable reference.
Transcendental functions supplied in the Zilog BASIC pack-
age use the powerful technique of rational approximations
to limit the number of arithmetic operations performed in
their evaluation while guaranteeing accuracy. The fundamen-
tal arithmetic operations all use rounding of results rather
than truncation to further enhance system accuracy. The
Interpreter itself maintains all variable references in an en-
coded form to eliminate the need for execution time sym-
bol table searches. As a result of these advances, BASIC pro-
vides the convenience of an interpretive environment, speed
normally not found in an interpreter and random access to
disk files through a sophisticated disk operating system.
FORTRAN
N
FORTRAN has long been accepted as the standard for
scientific programming and is the "native" language of many
part-time programmers. Zilog supports FORTRAN with a
compiler conforming to the ANSI 1966 specification. This
level of FORTRAN is commonly referred to as FORTRAN
IV.
Full conformance, with the exception of COMPLEX data
types, to the generally accepted ANSI standard insures that
accumulated libraries of FORTRAN programs will be im-
mediately usable in the ZDS-1 environment. There is no
need to translate to a special microcomputer language.
Zilog FORTRAN opens the door to the richest traditions
of scientific programming in a small, inexpensive environ-
ment.
PLZ is Zilog's own family of system implementation lang-
uages. Designed specifically with the system programmer in
mind, PLZ provides an extremely sophisticated structured
programming environment. Implemented at two separate
language levels and in distinct translator packages, PLZ of-
fers a complete solution to microcomputer system program-
ming problems.
In its highest level, PLZ is a fully block structured lang-
uage with an IF-THEN-ELSE clause, a case selector (actual-
ly implemented in the syntax of the IF statement), block
REPEAT and EXIT statements, procedure references and,
of course, RETURN'S. Data types include BYTE, WORD,
INTEGER, SHORT INTEGER and POINTER as well as
ARRAYS of any type and RECORD'S composed of group-
ings of the various basic types, arrays, or even other records.
At this language level, both an Interpreter and a Compiler
are available. The interpreter provides a fast and convenient
means of program development and debugging, while the
highly efficient Compiler generates Z80 Object code.
For applications requiring total control of hardware re-
sources, a second level of PLZ provides all the block struc-
turing and control conventions of the full compiler, but
uses assembly language statements rather than compiler level
expressions and assignments. Thus, it acts as a PLZ compat-
ible structured assembler and produces code which can be
linked directly to modules translated by the compiler.
Regardless of the scope or complexity of a systems pro-
gramming problem, PLZ will provide a simple, elegant, and
complete environment for its solution.